Those numbers are two decades old. Shortly after they were made public there was a union negotiation with UAW where new employees were permitted to have far few

Those numbers are two decades old. Shortly after they were made public there was a union negotiation with UAW where new employees were permitted to have far fewer healthcare and retirement benefits. It's been 20 years and GM has maintained a regular cadence of layoffs and buyouts for tenured workers, so the modern workforce is almost entirely those much cheaper employees.